Tension control



W. C. EWALDSON TENSION CONTROL Filed April 16, 1947 2 Sheets-Sheet 1 FIG./

INVENTOR W.C. EWALDSON By WM A T TORNEV W. C. EWALDSON TENSION CONTROL 2 Sheets-Sheet 2 Filed April 16, 1947 FIG-2 unumw lmmmuimmmulmuiul INVENTOR WC. [WALD-SON A TTORNEY I l I Patented July 5, 1949 TENSIGN CONTROL Waldemar C. Ewaldson, Millington, N. .l., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application April 16, 1947, Serial No. 741,920

3 Claims.

This invention relates to tension controls for continuous flexible elements, and more particularly to a tension control for a Fourdrinier wire in a pulp insulating machine for forming insulating coverings of pulpous material on electrical conductors.

The Fourdrinier wire in the pulp insulating machine is driven about its supporting rollers, the upper portion of the wire travelling with the conductors in the area where the pulpous material is applied to the conductors. The electrical conductors in this area are guided in a common plane and maintained taut by the introduction of a given tension in the conductors. It is important that the Fourdrinier wire have a given tension created therein to cause the upper portion thereof travelling with the conductors to lie in a given plane substantially parallel with the said plane of the conductors to control the even formation of the paper pulp about the conductors.

An object of the invention is to provide a tension control for a continuous flexible element, particularly a Fourdrinier wire which is simple in construction, highly accurate and readily actuable.

With this and other objects in view, the invention comprises a tension control for a continuous flexible element mounted on spaced supporting rollers and driven linearly, the tension control including a tension roller positioned to engage the element at a position spaced from the supporting rollers, a support therefor, and means to move the support to cause the tension roller to apply a variable force to the element to create a variable tension in the element.

More specifically, the tension control is for a Fourdrinier wire in a pulp insulating machine for forming an insulating covering of pulpous material on a plurality of electrical conductors as they advance longitudinally in a plane parallel with and adjacent the wire, while the Wire is driven about spaced supporting rollers. The tension control includes a tension roller equal to or greater in length than the width of the Fourdrinier wire and positioned transversely of the wire. The tension roller is supported by a pivotal frame which is movable relative to the wire by a threaded shaft carried by an element, in the form of a yoke, pivotally connecting one end of the threaded shaft to the frame. A fixed position housing, apertured for the threaded shaft to extend therethrough has a nut longitudinally movable therein through which the threaded shaft exends, the nut being backed up by a compression spring which is also disposed in the housing concentric with the threaded shaft. The tension created in the Fourdrinier wire originates in the spring and as the spring is compressed, the tension in the wire increases. A dial positioned adjacent the housing is graduated to indicate the tension in the wire. A pointer movable relative to the dial is driven by a rack carried by the nut and interengaging a pinion concentric with z. pivotal support for the pointer and fixed there- Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein 7 Fig. 1 is a schematic side elevational view of a portion of a pulp insulating machine illustrating the invention;

Fig. 2 is an enlarged fragmentary detailed viewof the tension control;

Fig. 3 is a fragmentary sectional view taken along the line 33 of Fig. 2; and

Fig. 4 is a fragmentary sectional view taken along the line 4-4 of Fig. 2.

Referring now to the drawings, the portion or unit IU of the pulp insulating machine selected to illustrate the invention includes supporting rollers II and I2 for a continuous flexible element M which in the present embodiment is a Fourdrinier wire. The upper portion l5 of the wire travelling in the direction of the arrow between the supporting rollers II and [2 travels through an area where a pulpous material (not shown) is fed to the wire around a plurality of electrical conductors l6 guided to and through the material applying area by sheaves ll, I8 and IS. The tension in the conductors l6 causes the portions of the conductors between the rollers 18 and I9 to lie in a given plane. It is important therefore that the portion l5 of the wire l4 lie Within a given plane parallel to the plane of the conductors to cause uniform formation of the pulpous material about the conductors. If the wire is not held taut between the rollers ll and I2 and is allowed to sag, it is apparent that the pulpous material may not surround the conductors between the sheaves l8 and I9. Furthermore, undue tension created in the Fourdrinier wire may damage the wire and for this rason, it is important that the proper tension be maintained in the wire. This is brought about through the tension control mechanism, assisted by an idler roller 20.

The tension control mechanism includes a tension roller 2| which is equal to or greater in length than, the width of the Fourdrini-er wire and is positioned transversely of the wire as shown in Figs. 1, 2 and 4. The roller 2| is rotatably supported at the lower end of a frame 23, the upper end of the frame being pivotally supported at 24 on a downwardly extending bracket 25 of the main frame 26 which also rotatably supports the rollers II and [2. A crank shaft 28 is journalled in suitable bearings 28 in the frame 23 and has a hand crank 30 mounted on the outer end thereof. A yoke 32 has its legs provided with bearings 33 through which the shaft 28 extends and in this manner, the yoke 32 is supported by theshaft, the shaft being free to rotate in the bearings 33. The yoke 32 is also providedwith-a bearing 35 for rotatably supporting'a threaded shaft 36 1 which is held against axial movement in one direction by a fixed collar 3'l and'in the other'direction by a beveled gear 38. A companion beveled gear 39, fixedly mounted upon the crank shaft 28 and interengaging the beveled gear 38, IODEIQtiVGIY connects the crank shaft to the threaded shaft.

The "threaded shaft;36 extends through a housling=4l8zwhich .is.pivotallyisupported at M, which maybe describeda fixed :position, it being irnportant-that the housingi'beheld against move- :ment relative Ito 'the .tension roller 2i, but per- .rmitteditmpivot at Al during adjustment of the control mechanism to move the frame '23 about its pivot 24. A nut or threaded element 43 is :sliclably disposed-in theahousing 19 and carries -a rack 44 "which extends through a slot 'in t-theLupper Wall of 'the housing. The rack 64 interengages a pinion 46 which is mounted on a shaft M'Iof a'pointer The-pointer 48 is movable :relative to a dial 49 having graduations -50 to indicate the pounds pressure applied to the wire '14 through the tension control mechanism. The force to create variable itensions in the wire originates in a compression spring 52 disposed in the housing 40 concentric with the threaded :shaft 36'back of the nut '43. The nature of'the spring 52 is such that as the-spring-is compressed by-the nut 43, causing rotation of the pointer 48-relative'to the dial FQ, a' known force, indicated by the'pointer, will he applied to'the wire 14.

The tension control'mechanism is located at a position where it is possible for the operator to determine readily'at-any time the tension in the wire and vary the tension without stopping the machine. This is accomplished by rotatingthe'crank'iin clockwise'to reduce the tension and counterclockwise to increase the tension. For example, letitbeassumed that the operator wishes to increase the tension in the wire M. This is brought-about by rotating the crank "-39 counterclockwise to rotatethe'crank shaft 23 to drivethe gears 39 and 38 torotate the threaded shaft36 in a direction whereby it will move to the leftinthe nut 43. By rotating the threaded shaft 36'in'the direction specified; the distance between the nut 43 and the.yoke"32'is widened, simultaneously compressing'the'spring .52 to increase the force therein and applyingthis force to the wire through the pivotal frame 123 and the tension roller 2|. It will therefore be apparent that as the threaded shaft C36moves the nut 43 to the right to.compress the spring 52, the shaft will bemoved to 'thele'ft'to cause clockwise vmove? ment of the frame "23 aboutits pivot 24, to move the tension ro1ler'2l outwardly to'increase the tension in the .wire M.

In a similar manner,the'tension in the wire M may be decreased "by rotating the crank "30 in the opposite direction to cause rotation of 4 the threaded shaft 36 in the threaded element 43 to release a given amount of the force created in the spring 52 reducing the force applied to the wire through the control mechanism.

At all times, the tension in the Fourdrinier wire depends on the force created in the spring. Furthermore, the force in the spring depends on 'theposition of "the nut '43 relative to the right end of the housing 40, and for this reason movement of the nut will cause actuation of the pointer 48 relative to the dial 49 to indicate the force applied to the wire or the tension created therein. Any action of the crank 30 to vary the tension in the wire M will cause movement of the pointer to'notify the operator, at all times, the tension in the wire.

Although specific improvements of the invention have been shown and described, it will be understood that they are but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as: defined by the appended claims.

What is claimed is:

'1. A tension control for aFourdrinier wire in a pulp insulating machine'for forming an insulating covering of paper pulp on a plurality of electrical conductors as they advance longitudinally in parallel guided paths adjacent the wire while the wire is driven about spaced supporting rollers, the tension control comprising a tension roller equal to or greater in length than the width of the wire and positioned transversely of the wire, a pivotal frame supporting the tension roller, a threaded shaft, an element rotatably supporting the shaft pivotally connected to the frame, a fixed position housing apertured for the threaded shaft to extend therethrough, a nut threadedly mounted on the shaft and movably disposed in 'the housing, a compression spring disposed back of the nut concentric with the shaft to urge the shaft to -move the frame to cause the tension roller to create'a given tension in the'wire, and means to cause rotation of the shaft relative tothe'nut to vary the compression of the spring to vary the tension in the wire.

2. A'tension control'for a Fourdrinier wire in 'a pulp insulating machine forforming an insulating covering of paper pulp on -a plurality of electrical conductors as they-advance longitudinally in parallel guided paths adjacent the wire while thewire is driven about spaced supporting rollers, the tension control comprising a tension roller equal to or greater'in length than the width of the wire and positioned transversely of the wire, a pivotal frame supporting the tension roller, a threaded shaft, an element rotatably supporting the shaft pivotally connected to the frame, a fixed position. housing apertured for the threaded shaft to extend therethrough, a nut threadedly mounted on the shaft and movably disposed in the housing, a compression spring disposed back of the nut concentric with the shaft to urge .the shaft to ,move 'the frame to cause the tension roller .to create a given tension in the wire, means to rotate the. shaft relative to the nut to vary thedistance between the nut and the frame to vary the compression of the spring resulting in movement of the nut in the housing. and variation of the tension in the wire, and indicatingmeans actuable by the movement .of the nut in the housing toindicate'the tension in 'the wire.

'3. Atension 'control for a Fourdrinier wire in apulp insulating machine for forming an insulating covering of paper pulp on a plurality of electrical conductors as they advance longitudinally in parallel guided paths adjacent the wire while the wire is driven about spaced supporting rollers, the tension control comprising a tension roller equal to or greater in length than the width of the wire and positioned transversely of the wire, a pivotal frame supporting the tension roller, a threaded shaft, an element rotatably supporting the shaft pivotally connected to the frame, a fixed position housing apertured for the threaded shaft to extend therethrough, a nut threadedly mounted on the shaft and movably disposed in the housing, a compression spring disposed back of the nut concentric with the shaft to urge the shaft to move the frame to cause the tension roller to create a given tension in the wire, a drive shaft rotatably supported by the frame, gears operatively connecting the shafts, and a crank mounted on the 6 drive shaft externally of the frame to rotate the drive shaft, whereby the threaded shaft will be rotated relative to the nut to vary the compression of the spring to vary the tension in the wire.

WALDEMAR C. EWALDSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 598,658 Gilman Feb. 8, 1898 1,744,746 Brown Jan. 28, 1930 FOREIGN PATENTS Number Country Date 84,672 Switzerland Aug. 20, 1920 

